// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_RENDERER_DEVTOOLS_RENDER_WIDGET_SCREEN_METRICS_EMULATOR_H_
#define CONTENT_RENDERER_DEVTOOLS_RENDER_WIDGET_SCREEN_METRICS_EMULATOR_H_

#include <memory>

#include "content/common/resize_params.h"
#include "third_party/WebKit/public/web/WebDeviceEmulationParams.h"

namespace gfx {
class PointF;
class Rect;
}

namespace content {

class RenderWidgetScreenMetricsEmulatorDelegate;
struct ContextMenuParams;

// RenderWidgetScreenMetricsEmulator class manages screen emulation inside a
// RenderWidget. This includes resizing, placing view on the screen at desired
// position, changing device scale factor, and scaling down the whole
// widget if required to fit into the browser window.
class CONTENT_EXPORT RenderWidgetScreenMetricsEmulator {
public:
    RenderWidgetScreenMetricsEmulator(
        RenderWidgetScreenMetricsEmulatorDelegate* delegate,
        const blink::WebDeviceEmulationParams& params,
        const ResizeParams& resize_params,
        const gfx::Rect& view_screen_rect,
        const gfx::Rect& window_screen_rect);
    virtual ~RenderWidgetScreenMetricsEmulator();

    // Scale and offset used to convert between host coordinates
    // and webwidget coordinates.
    const gfx::Size& original_size() const
    {
        return original_resize_params_.new_size;
    }

    float scale() const { return scale_; }
    const gfx::PointF& offset() const { return offset_; }
    const gfx::Rect& applied_widget_rect() const { return applied_widget_rect_; }
    const ScreenInfo& original_screen_info() const
    {
        return original_resize_params_.screen_info;
    }
    const gfx::Rect& original_screen_rect() const
    {
        return original_view_screen_rect_;
    }

    void ChangeEmulationParams(const blink::WebDeviceEmulationParams& params);

    // The following methods alter handlers' behavior for messages related to
    // widget size and position.
    void OnResize(const ResizeParams& params);
    void OnUpdateWindowScreenRect(const gfx::Rect& window_screen_rect);
    void OnUpdateScreenRects(const gfx::Rect& view_screen_rect,
        const gfx::Rect& window_screen_rect);
    void OnShowContextMenu(ContextMenuParams* params);
    gfx::Rect AdjustValidationMessageAnchor(const gfx::Rect& anchor);

    // Apply parameters to the render widget.
    void Apply();

private:
    RenderWidgetScreenMetricsEmulatorDelegate* const delegate_;

    // Parameters as passed by RenderWidget::EnableScreenMetricsEmulation.
    blink::WebDeviceEmulationParams emulation_params_;

    // The computed scale and offset used to fit widget into browser window.
    float scale_;
    gfx::PointF offset_;

    // Widget rect as passed to webwidget.
    gfx::Rect applied_widget_rect_;

    // Original values to restore back after emulation ends.
    ResizeParams original_resize_params_;
    gfx::Rect original_view_screen_rect_;
    gfx::Rect original_window_screen_rect_;

    DISALLOW_COPY_AND_ASSIGN(RenderWidgetScreenMetricsEmulator);
};

} // namespace content

#endif // CONTENT_RENDERER_DEVTOOLS_RENDER_WIDGET_SCREEN_METRICS_EMULATOR_H_
